The invention relates to a receiving apparatus for receiving a plurality of transmitted signals, comprising tuning means for selecting a selected signal from the transmitted signals in response to control signals, first signal processing means for extracting and processing a first type of information from the selected signal, and second signal processing means for extracting and processing a second type of information from the selected signal, the receiving apparatus having a coupled state in which an input of the first signal processing means is effectively coupled to an output of the tuning means, and a decoupled state in which the input of the first signal processing means is effectively decoupled from the output of the tuning means.
Such a receiving apparatus is widely known. For example, a digital television receiver comprises tuning means for receiving a plurality of TV-channels, which carry transport streams comprising video and audio information, constituting the first type of information, as well as system information (SI), constituting the second type of information. A digital television receiver generally comprises an audio processor and a video processor, constituting the first signal processing means, and a microprocessor, constituting the second signal processing means.
Many television receivers offer the possibility to view other signals than those acquired via the tuning means, e.g. recordings from a VCR or images from a camera. If the other signals are obtained through a SCART input, the tuning means are effectively decoupled from the audio and video processor. This situation is considered to exist as well in a stand-by or power-off mode, because in such cases there is no transport of signals between the tuning means and the first signal processing means.
Most TV-stations incorporate electronic program information (EPG) presenting programs which are scheduled to be transmitted via that particular TV-channel. For an end-user it is difficult to get an overview of the programs of all channels, because the information is scattered over multiple channels, which makes it very cumbersome to collect the information.
In EP 0 774 868 A1 a television system is described, requiring a compound EPG to be transmitted in advance, which EPG comprises information about the scheduled programs of a large number of channels. The system provides a number of features to manage the large amount of information, e.g. searching and filtering. Programs of different channels can be presented in one time-table, and a user may select one or more program categories. The user is enabled to enter search requests, as a result of which the system tries to find the requested items in the compound EPG. Another option is the notification of the user that a particular program is about to be transmitted. Such a compound EPG is a large improvement over EPG information which is scattered over various channels.
This example shows that it can be very convenient to collect information from various sources and make it available to a user in a compound form. A disadvantage of the known system, however, is that the compound information has to be composed in advance and transmitted through a dedicated channel, thus requiring additional transmission capacity.
An object of the present invention is to provide a receiving apparatus which provides the user with compound information, composed from information incorporated in multiple signals, without the requirement that the compound information is composed in advance and transmitted through a dedicated signal.
To achieve this object, the receiving apparatus according to the invention is characterized in that the receiving apparatus further comprises controlling means which are conceived to generate the control signals for controlling the tuning means when the receiving apparatus is in the decoupled state, said control signals being chosen such that the tuning means successively select a respective signal from at least a number of the transmitted signals, the second processing means being further conceived to extract and process the second type of information from each selected signal. When the apparatus in the decoupled state, i.e. effectively decoupled from the tuning means because the first signal processing means are processing signals not obtained from the tuning means or because the apparatus is in a stand-by mode, the tuning means can be utilized for the scanning process.
A preferred embodiment of the receiving apparatus is characterized in that the second processing means are further conceived to extract an electronic program guide (EPG) from the second type of information. scanning signals for EPG information during e.g. stand-by mode is very profitable, because EPG information is scattered over many signals and updated every day. In a preferred embodiment the second processing means are further conceived to combine EPGs from at least two of the transmitted signals into a compound EPG. Such a compound EPG is very convenient for a user and by performing these activities during e.g. stand-by mode, delays in the operation of the apparatus and in the availability of the EPG information are avoided.
A further embodiment of the apparatus according to the invention is characterized in that the controlling means are conceived to initiate the generation of the control signals for controlling the tuning means automatically. As a consequence, the user does not need to activate the scanning of the TV-signals when the tuning means are not being used. Instead, the apparatus detects such a state and starts the scanning if appropriate, e.g. when certain information is expected to be updated.
In a preferred embodiment the apparatus is characterized in that the controlling means are conceived to generate the control signals in a stand-by mode of the apparatus. In stand-by mode, there is little chance that the scanning be interrupted by the user activating a feature which involves the tuning means.
A further embodiment of the apparatus is characterized in that the controlling means are conceived to generate the control signals in a power-off mode of the apparatus, the apparatus comprising a rechargeable battery for powering the receiving means during the scanning in the power-off mode. Many devices are completely switched off for long periods, because then no energy is required and the risk of fire is minimal. In this embodiment the apparatus according to the invention has a further power source for powering the circuits involved in scanning the signals and storing the information obtained. Preferably this power source is rechargeable, the receiving apparatus further comprising charging means for charging the power source in a power-on mode.
It is to be noted that the German patent application DE 42 40 187 A1 discloses a TV-set which comprises a second tuner and additional second signal processing means for scanning TV signals EPG information, the additional second signal processing means being adapted to compose a compound EPG from the acquired EPG information. The compound EPG comprises program information from all TV stations for which EPG information was extracted from the signals. It can be inspected by means of the television screen. A disadvantage of this invention is that for scanning the TV signals an additional tuner and additional second signal processing means are required, which makes the apparatus more expensive.
The invention can be profitably applied to television receivers, but it can be applied equally well to, for instance, radio receivers.